Replacement of fertilizers with sludge and rubber latex lutoid for nursering poly-bag rubber (budded
stump RRIM 600) was conducted at agricultural area tambon Saikhueng, Phrasang district, Suratthani
Province. The treatments were arranged in Randomized Complete Block Design (RCBD) with 5 replications.
The treatments were control, organic fertilizer cum rock phosphate fertilizer and chemical fertilizer, sludge
cum rubber latex lutoid, and sludge cum rubber latex lutoid and chemical fertilizer. The result showed that
chemical fertilizer and organic fertilizer could be replaced by sludge cum rubber latex lutoid equally or better
off significantly. Both amendments could increase organic matter content, sufficiently supplied major
elements (N, P, K) and Mg for growth of poly-bag rubber (height, diameter, size of canopy and dry weight of
root) and basal application of rock phosphate fertilizer (170 grams/tree) in the field was not needed.